The cost of surface treatment varies and therefore it is good to know what you are charged for before you place an order for thermal spray coating.
Part Size and Surface Area
Part Size: Larger parts take longer to complete processing, therefore are normally priced on surface area, weight, etc. The processing of a long shaft or a wide plate is likely to cost more than processing a small component, therefore it is wise to calculate an approximate surface area before requesting a quote for any surface treatment.
Choice of Spray Material
Another variable that affects the cost of surface treatment work is the spray material used. Generally the cost of spray material is a function of its density, but there are large cost differences between similar materials. Zinc wire, for example, is one of the cheaper spray materials and is suitable for general corrosion protection. Tungsten carbide is a more expensive spray material and is used where a hard, wear resistant surface is required. The cost of ceramic materials varies between grades, but generally they are somewhere between zinc wire and Tungsten carbide.
Substrate Condition and Pre-Treatment
Parts arriving with heavy corrosion, scale or previous coating will require additional preparation before spraying can commence. The typical method of preparation for thermal spray coating would be grit blasting. However, badly corroded surfaces may require additional cleaning passes and possibly some mechanical cleaning before spraying can commence. The cost of cleaning will form part of the base price for the coating.
Coating Thickness and Number of Passes
Work to thicker coatings require more material (i.e. more spray passes) and, consequently, are more expensive. A thinner coating, for example, might be acceptable for a bearing seat and, consequently, will be less expensive to apply. A good surface engineering specification (e.g. as provided by the Institution of Mechanical Engineers) enables coatings to be specified for the correct application.
Masking Complexity
Masking the various components on your parts, for example bearing seats, external threads, etc can be very time-consuming especially for intricate masks. The complexity of the masking will definitely add to the labour cost of the project.
Batch Size
Single-part jobs have a set-up cost that can be spread when an order for identical parts is placed. A useful reference for Thermal Spray Coating is https://www.poeton.co.uk/surface-treatments/thermal-metal-sprays.
An accurate quote for surface treatment can be supplied once the relevant factors for your parts have been established.
